The first ever computer was built in 1940s, it used vacuum tubes; it weighed 30 tons and had occupied an entire room. With the developing technology computers have advanced to a great extent and thus became faster, smaller, cheaper and more reliable. Microchips are most advanced and important development. Every chip is made of sleek slim thin sheet of silicon about one quarter inch square with millions of nano electrical circuits clinged on to the surface using microphotography.

Through these tiny electrical circuits, current flows so quickly and the computing speed is measured in billionths of a second. There are varieties of tasks which can be added to the personal computer using these chips. The two most important chips used in PC are RAM and ROM.